1. Field of the Invention
The present invention relates to a hollow weather strip having a slit and a slot at a back surface thereof, particularly to an improvement of a connecting portion between an extrusion portion and a mold portion.
2. Prior Art
First, second and third prior art weather strips are illustrated in FIGS. 1 through 3. Employed in the same figures, a symbol denoted at, i.e. a reverse isosceles triangle which is partitioned by a center line extending from a vertical angle thereof wherein one half is white and the other is painted over with black. The portion painted over with black represents a mold portion and a portion which is not painted over with black represents an extrusion portion. As a structure of a connecting portion between the extrusion portion and the mold portion of a hollow weather strip having a slit and a slot respectively at a back surface thereof, there has been generally employed a structure as illustrated in FIG. 1 in which a mold portion 20 has a slot 21 width of which ranges from 2 to 4 mm at a back surface thereof in a longitudinal direction thereof, and an extrusion portion 10 has a slit 11 at an end back surface thereof. A width of the slit 11 is smaller than that of the slot 21.
However, the first prior art weather strip has a problem in that since the extrusion portion 10 and the mold portion 20 have the same width Y at back surfaces thereof, the width of the mold portion 20 is smaller than the width Y when the slit 11 and the slot 21 are closed by adhesive respectively for holding the shape of the weather strip, which mars an external appearance of the weather strip. To improve this problem, the width of the back surface of the mold portion 20 is larger than the width Y of the extrusion portion 10 by a width Z of the slot 21 shown in FIGS. 2 and 3, which permits however the widths of the mold portion 20 and the extrusion portion 10 at the connecting position thereof to remain the width Y of the extrusion portion 10, which causes a problem in that the widths of the slit 11 and the slot 21, after the slit 11 and the slot 21 are closed by adhesive respectively, are not uniform. As a result, it is inevitable that an external appearance of the weather strip is marred. The slot 21 is provided to serve a hole to eject a core of a mold in a molding process of a mold portion to hollow the mold portion.
However, the prior art weather strip has such a problem in that when the slit 11 and the slot 21 are closed by adhesive respectively for holding the shape of the weather strip, widths of the slit 11 and the slot 21 are not uniform after they are closed by adhesive respectively which mars an external appearance thereof.